In the context of oxidative coloring and also oxidative lightening of hair, the problem arises that irritation of the scalp and damage to the keratinic fibers can occur as a result of the aggressive agents. In particular, the natural hydrophobicity of the keratinic fibers is reduced because the coloring agents resp. lightening agents must first make the hair capable of penetration in order to exert their effect. The water-repellent effect on the one hand, however, provides natural protection for the hair; on the other hand, parameters desired by the consumer, such as shine, softness, suppleness, and the “drape” of the hair, are closely linked to it.
In order to overcome the aforesaid disadvantages, so-called post-treatment agents that are intended to compensate for hair damage caused by the oxidizing agent are on the market. These often make the hair heavy, however, or negatively affect the outcome of the previously performed lightening resp. coloring of the hair; in particular, the washing fastness of the color can be degraded by the post-treatment agent.
An object of the present invention is to make available a method for oxidative hair treatment, with a hair-protecting post-treatment, that overcomes the aforesaid disadvantages without counteracting the success of a previously performed oxidative hair treatment. The intention is in particular to make available a method in which the hair is not made heavier, and in which the desired effect can also be achieved in the context of a post-treatment not occurring immediately after the oxidative hair treatment, with the result that the time span between oxidative hair treatment and post-treatment can be extended.